cfg80211: Fix validation of AKM suites
Incorrect variable was used in validating the akm_suites array from
NL80211_ATTR_AKM_SUITES. In addition, there was no explicit
validation of the array length (we only have room for
NL80211_MAX_NR_AKM_SUITES).
This can result in a buffer write overflow for stack variables with
arbitrary data from user space. The nl80211 commands using the affected
functionality require GENL_ADMIN_PERM, so this is only exposed to admin
users.
Cc: stable@kernel.org
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index e83e7fe..ea40d54 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -4113,9 +4113,12 @@
if (len % sizeof(u32))
return -EINVAL;
+ if (settings->n_akm_suites > NL80211_MAX_NR_AKM_SUITES)
+ return -EINVAL;
+
memcpy(settings->akm_suites, data, len);
- for (i = 0; i < settings->n_ciphers_pairwise; i++)
+ for (i = 0; i < settings->n_akm_suites; i++)
if (!nl80211_valid_akm_suite(settings->akm_suites[i]))
return -EINVAL;
}